Alternating-current commutator dynamo-electric machine.



W. DOINIKOFP. ALTERNATING CURRENT OOMMUTATOR DYNAMO ELECTRIC MACHINE.

APPLIUATION FILED SEPT. 28, 1908.

1,038,861 PatentedSept. 17, 1912.

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. 3, M/ITNESSES W. DOINIKOPF.

ALTERNATING CURRENT OOMMUTATOR DYNAMO ELECTRIC MACHINE.

' APPLIGATiON FILED fill-P128, 190s.

w r- 1 1,038,861, I Patented Dept. 11,1913.

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end the consequent dis 'jlscemcnt of the c( STATES PATENT OFFICE.

WLADIMIR DOINIKOFF, OF KARLSRUHE, GERMANY.

ALTFI'JitlNAlFING-(TUREENT COMMUTATOR DYNAMIC-ELECTRIC MACHINE.

Original application filed March 6, 1808, Serial No. 419,537. Divided and this 28, 1908. Serial No. 455,151.

Specification of Letters Patent.

Patented Sept. 17, 1912.

application filed September which resulted in Patent No. 907,57 8, dated December 22, 1908, relates to means for suppressinc spsrla at the brushes of compensated single-phase dynamo electric machines. In said patent, there shown and described means the general purpose indicated, applied to single-phasedynamo electric mocliines, involving a. somewhat more complicat-ed arrangement of compensating devices, more particulu y exemplified in Figures 11, 1d and 17 of so lpatent. Each of said compensating devices, as illustrated in thepatent, includes a t nsformer which supplies current to the wir s of the ccmmutating poles connected with lflCi poles, in accordance with o definite rule laid down in said pat to wit, the connections between the wn sings on the said transformer and the exciting? windings for the comn'iutat-ing pole lyuig b tween the ends of chords which are .d through an angle 99, "iinished to the extent of zip- -ro:;lnistcljI segment breadth plus half a brush breadth 1" cm the ofthe brushes, ively to the connecting points of the 1 connections. As described in the origie specification or. the "patent aforesaid, "cut-"invention relates to a greatly simpl ed means for supplying the cxcitil'ig windin s' to the compensating poles of compenssted single-phase machines, without involving the application of a transformer nections between said trnnsiformer and the brushes with respect. to the axis of the brushes.

The invention is illustrated in the accompanying drawings, in which,

Figs. 1, 2, 3 and 4 are diagrammatic representations of the application of the invention to compensated single-phase dynamo electric machines. Fig. 5 is a complete diagram of a machine involving the invention. Fig. 6 is a diagram of the commutator potential curve developed by a machine of the type shown in F ig. 3.

The present invention is directed to compensated single phase dynamo electric machines, in which at least one pair of brushes is short-circuited, so that, unlike certain of the machines described in the prior patent aforesaid, the commutator potential curve does not rotate, but, on the other hand,

takes the form of an ordinary sign curve whose ordinates pulsate in uniform phase, as indicated in Fig. 4'.

In the types of machines shown in Figs. 1 and 8, each of which are provided with four brushes, 13,, B. B B cooperating with commutator C, T T indicate the line terminals, A, the stator or field winding, the armature winding being omitted to avoid complication, and the two brushes B, and B, being sl1ort-circuitcd, said brushes being located permanently at the same points of the commutator potential curve, as indi cated in Fig. 6. In the modification shown inFigs. 2 and 4, each of which involves. three brushes 1%,, B 13,, cooperating with commutator C, brushes B, and B are shortcircuited. Each of these figures may. therefore, be reqarded as a diagrammatic presentution of well known types of compensated single phase machines, in which at least'two brushes are short-circuited.

Inasmuch as the same principle of con- StI'KLJUOIl and operation is present- 1n the several modifications of the machine, indi- ,nent of compensating device according to the invention. I

11 Fig. 5, A, indicates the stator or field windings, A the main armatlire or rotor winding, A an auxiliary armature, preferably in the form of a laminated ring, having windings thereon which are connected to the coils of the rotor winding A and the segments of the commutator C respectively, and which are influenced by the commutating poles in such a manner that the commutator curve at he places where the brushes ,:poles for the exciting are located, is flattened, which has the effect of preventing a short-circuit current be tween the two edges of each brush, which current would give rise to sparking, as par ticularly set forth in'my patent aforesaid. The commutating poles 3/ p,,' p,, p,,' 7/ p 7%,, p,, as indicated, are located in pairs over the brushes B B B B respectively, and serve to diminish the influence of the commutation of the brush current. and in a large measure to suppress sparking at the brushes.

T and T arev the terminals of the machine, the former of which is connected to the field Winding, which in turn is connected to brush 3,, the latter terminal T being connected directly with brush 3,, so that the course of the current is from'terminal T, A brush B Wlndings on auxiliary armature A rotor winding A, brush B to terminal T and conversely. As indicated in the diagram, the exciting windings of the several com-.

mutating and are connected poles are in series with each other,

exciting current for the compensating pole windings is supplied by a current having a potential difference equal to that of the brushes B, and mits or flattest tential curve. tion, the number of turns on the poles opposite the brushes B and B is less than that on the poles opposite brushes B and 13,. By properly proportioning the number of turns of the windings of the respective com inutator poles, the correction by the lateral displacement of the commutator poles, as indicated in the parent case, may be obviate Under certain conditions, it-may not be found, necessary to provide compensating brushes B and B inwhich event, the construction diagrai matically indicated in Fig. 1 may be followed, the machine being in all other re- Figs. 2- andl; are

spects, similar to that indicated in Fig. 3.

.vVhen machines of the types shown in employed, said machines 7 having three brushes, two of which are short-cirmilted, compensat ng poles may in parallel between the leads of the brushes B and B,, so that the 3,, which are at the sum: parts of the commutator p0- Because of this latter condiprovided for each of the brushes, as indicated in Fig. 4:, or, in the alternative, compensating poles may be provided for the short-circuited brushes B and B, only, as indicated in Fig. 2, in each' case, however, the exciting windings for the compensating poles receive current from brush 1;, and the, short-circuit connection between brushes B and E the several compensating pole windings, in both forms of the apparatus being in series.

Obviously, the branching points of the eX- citing windings of the commutating poles in the several modifications-may be located at any oints of the commutator, which are at a su cient potential difference to energize the said windings to effect the desired result, and therefore, the displacement of these branching points through an angle of 90 is not" necessary, in the several forms of the invention illustrated, in which particular, the present invention is distinguished from the specific forms of the invention as disclosed in my prior Letters Patent aforesaid,

and furthermore, the exciting current for the compensating poles may be derived directly from the wo king commutator brushes for the main leads of the machine Without the interposition of a transformer,

such as was employed in the same general of machine in the ty e patent aforesaid.

l Vhat I claim is 1. Mechanism for preventing sparking at the brushes of compensated single phase dynamo electric machines, having two short circuited brushes, a main armature winding, a commutator, connecting wires between the said winding and commutator; comprising an auxiliary armature iron core, upon which the said connecting wires are Wound, commutating poles, adapted to influence the said connecting wires in such a manner that the commutator potential curve at the places where the brushes are situated is flattened, windings on the said commutating poles, and direct connections be-- tween the windings of the said commutating poles and the said commutator, the said windings being in series between points of the said commutator which are at a sufficient potential difference for feeding the said windings.

2. Mechanism for preventing sparking at the brushes of compensated single phase dynamo electric machines, having a main armature winding, a commutator, two pairs of brushes, one of said pairs being short circuited, connecting wires between the said winding and commutator; comprising an auxiliary armature iron core upon which the said connecting wires are mutating poles adapted to influence the said connecting wires in such a manner that the commutator potential curve at the places Wound, com-\ where the brushes are situated is flattened, adjacent the short circuited brushes being 10 windings on the said commutating poles, greater than that of the other poles.

and direct connections between the wind- In testimony whereof I have affixed my ings of the said commutating poles and the signature, in presence of two witnesses.

. said commutator, the said windings being in WLADIMIR DOINIKOFF.

series between points of the said commutator which are at a sufficient potential difference Witnesses:

for feeding the said windings, the number of N. R. SHANK, ampere turns in the windings of the poles Jos. H. LEUTE.

Copies of this patent may be obtained for five cents each, by eddressing the Commissioner of Patents,

Washington, D. O. 

